package com.laulkar.dataproviders;

import java.util.ArrayList;

import android.content.ContentValues;
import android.content.Context;
import android.database.CharArrayBuffer;
import android.database.Cursor;
import android.database.SQLException;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;
import android.util.Log;

public class SubwayDbAdapter {

	public static final String KEY_LINE = "line";
	public static final String KEY_STATUS = "status";
	

	private static final String TAG = "SubwayDbAdapter";
	private DatabaseHelper mDbHelper;
	private SQLiteDatabase mDb;

	/**
     * Database creation sql statement
     */
    private static final String DATABASE_CREATE =
        "create table subway_status (line text not null, status text not null);";

    private static final String DATABASE_NAME = "data";
    private static final String DATABASE_TABLE = "subway_status";
    private static final int DATABASE_VERSION = 2;

    private final Context mCtx;

    private static class DatabaseHelper extends SQLiteOpenHelper {

        DatabaseHelper(Context context) {
            super(context, DATABASE_NAME, null, DATABASE_VERSION);
        }

        @Override
        public void onCreate(SQLiteDatabase db) {

            db.execSQL(DATABASE_CREATE);
        }

        @Override
        public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
            Log.w(TAG, "Upgrading database from version " + oldVersion + " to "
                    + newVersion + ", which will destroy all old data");
            db.execSQL("DROP TABLE IF EXISTS subway_status");
            onCreate(db);
        }
    }

    /**
     * Constructor - takes the context to allow the database to be
     * opened/created
     * 
     * @param ctx the Context within which to work
     */
    public SubwayDbAdapter(Context ctx) {
        this.mCtx = ctx;
    }

    /**
     * Open the notes database. If it cannot be opened, try to create a new
     * instance of the database. If it cannot be created, throw an exception to
     * signal the failure
     * 
     * @return this (self reference, allowing this to be chained in an
     *         initialization call)
     * @throws SQLException if the database could be neither opened or created
     */
    public SubwayDbAdapter open() throws SQLException {
        mDbHelper = new DatabaseHelper(mCtx);
        mDb = mDbHelper.getWritableDatabase();
        return this;
    }

    public void close() {
        mDbHelper.close();
    }


    /**
     * Create a new note using the title and body provided. If the note is
     * successfully created return the new rowId for that note, otherwise return
     * a -1 to indicate failure.
     * 
     * @param title the title of the note
     * @param body the body of the note
     * @return rowId or -1 if failed
     */
    public long createSubway(String subway, String status) {
        ContentValues initialValues = new ContentValues();
        
        initialValues.put(KEY_LINE, subway);
        initialValues.put(KEY_STATUS, status);

        return mDb.insert(DATABASE_TABLE, null, initialValues);
    }

  

    /**
     * Return a Cursor over the list of all notes in the database
     * 
     * @return Cursor over all notes
     */
    public ArrayList<Subway> fetchAllSubway() {

        Cursor c = mDb.query(DATABASE_TABLE, new String[] {KEY_LINE, KEY_STATUS}, 
        			null, null, null, null, null);
        if(c == null)
        	return new ArrayList<Subway>();
        ArrayList<Subway> subways = new ArrayList<Subway>(c.getCount());
        
        c.moveToFirst();
        Subway s = new Subway(c.getString(0), c.getString(1));
        subways.add(s);
        while(c.moveToNext())
        {
        	s = new Subway(c.getString(0), c.getString(1));
            subways.add(s);
        }
        c.close();
        return subways;
    }

    /**
     * Return a Cursor positioned at the note that matches the given rowId
     * 
     * @param rowId id of note to retrieve
     * @return Cursor positioned to matching note, if found
     * @throws SQLException if note could not be found/retrieved
     */
    public Subway fetchSubway(String line) throws SQLException {

    	try{   		
    	
        Cursor mCursor =
        	
            mDb.query(true, DATABASE_TABLE, new String[] {KEY_LINE,
                    KEY_STATUS}, KEY_LINE + "='" + line +"'", null,
                    null, null, null, null);
        if (mCursor != null && mCursor.moveToFirst()) {
        	Subway s =new Subway(mCursor.getString(0), mCursor.getString(1));
        	mCursor.close();
            return s;
        }
        else
        	return null;
    	}catch (Exception e)
    	{
    		Log.e("MSService", "Caught exception " + line);
    		return null;
    	}
    	
    }

    /**
     * Update the note using the details provided. The note to be updated is
     * specified using the rowId, and it is altered to use the title and body
     * values passed in
     * 
     * @param rowId id of note to update
     * @param title value to set note title to
     * @param body value to set note body to
     * @return true if the note was successfully updated, false otherwise
     */
    public boolean updateSubway(String subway, String status) {
    	ContentValues initialValues = new ContentValues();
        initialValues.put(KEY_LINE, subway);
        initialValues.put(KEY_STATUS, status);

        return mDb.update(DATABASE_TABLE, initialValues, KEY_LINE + "='" + subway +"'", null) > 0;
    }
    
    public boolean createOrUpdateSubway(String subway, String status) {
    	
    	if(updateSubway(subway, status))
    		return false;
    	else
    	{
    		createSubway(subway, status);
    		return true;
    	}
        
    }
}
